1. Field of the Invention
This invention relates generally to cassette tape recording and/or reproducing apparatus, and more particularly is directed to improvements in the devices provided in such apparatus for locating a tape cassette in respect to the head or heads by which signal recording and/or reproducing operations are performed.
2. Description of the Prior Art
It has been proposed, for example, in U.S. Pat. No. 3,743,299, issued July 3, 1973, and having a common assignee herewith, to provide a cassette tape recording and/or reproducing apparatus with a plurality of support members fixed on the chassis and having shouldered portions adapted to receive and support an edge portion of the cassette at a predetermined level in respect to the chassis, and a head supporting carriage which is slidably mounted on the chassis, for example, by pin and slot connections therebetween, for movement of the carriage relative to the chassis between an inactive position, in which each head on the carriage is spaced from a cassette operatively positioned on the support members, and an active position, in which each head is adapted to extend into a respective opening or window in the previously mentioned edge portion of the operatively positioned cassette for engagement with the tape in the latter. In order to maintain the positioning engagement of the mentioned shouldered portions of the support members with the edge portion of the cassette, particularly when the apparatus is portable so as to be subject to movement during recording and/or reproducing operations, the previously proposed apparatus has hold-down members or arms which are mounted on the head carriage. In the inactive position of the carriage, such hold-down members are spaced from the cassette so as to avoid interference with movement of the latter toward and away from its operative position on the support members. However, when the carriage is moved to its active position, the hold-down members move therewith to project over the edge portion of the operatively positioned cassette and to bear resiliently downward on the latter for maintaining the desired positioning engagement thereof with the support members. Since the hold-down members are mounted on the carriage, their downward resilient bearing on the cassette has an upward reaction on the carriage by which the latter may be upwardly deflected to vary the level of the head or heads thereon in respect to the tape in the operatively positioned cassette.
Further, in the previously proposed arrangement for locating the cassette, a resilient member acts against the edge portion of the operatively positioned cassette which is opposite the edge portion thereof seated on the shouldered portions of the support members or blocks so as to urge the seated edge portion against upstanding surfaces of such shouldered portions with a view to accurately and uniformly establishing the contact pressure of a head on the carriage against the tape in the operatively positioned cassette. However, if the hold-down members are allowed to bear down on the cassette during movement of the carriage to its active position, the frictional engagement of the hold-down members with the cassette tends to move the latter away from the upstanding surfaces of the shouldered portions with the result that the mentioned contact pressure is varied and the quality of signal recording or reproducing is deteriorated.